TRIGONOMETRICAL SURVEY OF INDIA. 191 



this should seem matter of surprise, still more extraordinary must the fact 

 appear, that until Captain Kater's experiments, there were measures 

 bearing the same denomination in our own country, none of which corres- 

 ponded, so that every instrument maker, when he constructed what he 

 called a standard scale, meant his own standard, which he had either arbi- 

 trarily fixed for himself or inherited from his predecessor. 



The want of a determinate idea as to the measures of antiquity, has 

 always been a subject of perplexity to Historians, — in fact, in consequence 

 of that defect, all the geographical details which we derive from that source 

 are a maze of conjecture for the ingenious to build airy hypotheses in. 

 Perhaps, however, this system, incongruous as it is, might have been suffi- 

 cient to answer the ordinary purposes of life, and, if the question had never 

 been started respecting the figure of the earth, would, in all probability, 

 have been but little agitated, if at all. 



This was at first a mere speculative question : it had been found by 

 M. Richer, a French mathematician, who went to make astronomical 

 observations at Cayenne in 1G72, that the pendulum of his astronomical 

 clock, which had been adjusted to mean time at Paris, lost above two 

 minutes every day, and he was obliged to shorten the pendulum one-tenth 

 of an inch to make it keep time in the latitude of 4' 55''''. Such was the 

 state of science at that period, (and we are not yet two centuries removed 

 from it,) that when he drew conclusions from this respecting the diminu-' 

 tion of gravity, his opinions were scouted by almost all lUc Philosophers 

 of Europe. Huygens was the first person who gave the subject fair con- 

 sideration, and as he brouglil willi liiiii an on ('r[)()\\ criiiL!,' ai ra\- of mathe- 

 matical reasoning, combined with incxhaiistihlc patience, he soon discov- 

 ered that pendulums must vibrate slower as tiioy ajiproach \hc (Mjualor; 

 but even Huygens could not solve llu- (lilii( iilly of assiuninu- the form 

 which the earth must assume. He made whdi wc should call the two 



